I will recheck it. I think it's related to heat. These light heads are so small compared to the 4500 lumen claims that they're too bright for the heatsinking available. We take readings at the the 30 second mark and our fan was tiny.

fc

With the ever increasing outputs in these tiny lamp heads, do you think it may be worth re-visiting the time frame the measurements are taken to achieve that products max output? Maybe the ten or fifteen second mark just to help rule out that some power houses are stepping down due to heat before the measurements are taken. The Olympia is also one that had been discussed as been majorly over stated, and that there should have been some decent improvement over last years model.

I understand by doing this it could alleviate motivation for these company's to improve their heat sinking

With the ever increasing outputs in these tiny lamp heads, do you think it may be worth re-visiting the time frame the measurements are taken to achieve that products max output? Maybe the ten or fifteen second mark just to help rule out that some power houses are stepping down due to heat before the measurements are taken. The Olympia is also one that had been discussed as been majorly over stated, and that there should have been some decent improvement over last years model.

I understand by doing this it could alleviate motivation for these company's to improve their heat sinking

For XC riding this year... I would say 1200-1400 lumens. That could be one 1200 lumen light on the bar or 700 on bar and 700 on the helmet.

Lumens get cheaper each year so I tend to ratchet up a little every year.

Generally:

- the faster you go, the more lumens you need so you don't outrun your light.

- the more people you ride with, the more lumens you need. That's because someone will have a super bright light and your eyes will adjust to their bright light.

What do others think?

fc

That sounds good to me. I think it's becoming more about beam shape than just pure lumens, because we have reached a point where all the lights put out enough light. If you have a light that puts 2000 lumens into a hotspot size of basketball it doesn't do you any good. You need some light between the tire and the hotspot, and some side-spill to see where you going. There is a lot of personal preference that comes into this as well. Some love the super-spot lights, where I prefer a floodier even beam. Some of the manufacturers are catching on to this, and providing different optics choices.

That sounds good to me. I think it's becoming more about beam shape than just pure lumens, because we have reached a point where all the lights put out enough light. If you have a light that puts 2000 lumens into a hotspot size of basketball it doesn't do you any good. You need some light between the tire and the hotspot, and some side-spill to see where you going. There is a lot of personal preference that comes into this as well. Some love the super-spot lights, where I prefer a floodier even beam. Some of the manufacturers are catching on to this, and providing different optics choices.

I just got the Lezyne Deca drive (800 lm) and it has plenty of light output on roads and fire roads.

I totally agree that the beam pattern is more of a factor now. Running that light at higher light output would just be a waste of battery power.

One thing I noticed on my Deca light is the cover lens appears to be replaceable. This has me thinking, "Can the cover lens be swapped to change the beam pattern to your liking?"

Lux is really not that relevant. It measures light output at a specific spot in the beam pattern.

We do something called Mtbr Lux which is the ambient lux reading of a light meter when the light is pointed at the ceiling in a controlled room. This number is really easy for us to get but it is only relevant to us for the basis of comparison. We used this a lot when we didn't have access to a $20,000 machine that measures lumens, an integrating sphere.

An integrating sphere measures lumens, which is the total output of a bike light. It measures by capturing all the light from a light and bouncing it on a sphere and collecting the light output. So lumens is the end all, be all for measuring light output.

Lux is really not that relevant. It measures light output at a specific spot in the beam pattern.

We do something called Mtbr Lux which is the ambient lux reading of a light meter when the light is pointed at the ceiling in a controlled room. This number is really easy for us to get but it is only relevant to us for the basis of comparison. We used this a lot when we didn't have access to a $20,000 machine that measures lumens, an integrating sphere.

An integrating sphere measures lumens, which is the total output of a bike light. It measures by capturing all the light from a light and bouncing it on a sphere and collecting the light output. So lumens is the end all, be all for measuring light output.

fc

Lumens ( when independently measured using an Integrating sphere ) are certainly a more useful metric than Lux.

however Lux i think can also be useful for measuring the "throw" of a light.

going by Lux alone is a good way to mislead the customer, but using Lux in addition to Lumens i think would be interesting and informative.

while it can be argued that the Tunnel beam pattern shots already convey the information about "throw" of the light, they do not do so in a way that can be easily entered into an excel spreadsheet.

Lumens ( when independently measured using an Integrating sphere ) are certainly a more useful metric than Lux.

however Lux i think can also be useful for measuring the "throw" of a light.

going by Lux alone is a good way to mislead the customer, but using Lux in addition to Lumens i think would be interesting and informative.

while it can be argued that the Tunnel beam pattern shots already convey the information about "throw" of the light, they do not do so in a way that can be easily entered into an excel spreadsheet.

Good points. I think it's too much detail and not enough background and it's hard to be consistent. A light with a very focused beam pattern will be rewarded with a high lux number. But then, that's really not what we want for biking.

In this FL1 document,http://www.streamlight.com/Documents/ansi/ansi-pres.pdf
The standard measure for light throw is determined by the distance where one can get a reading of .25 lux at the center. Unfortunately, that lux number is too low for these modern lights and I'll have to go hundreds and hundreds of yards to get to that low a reading for the big lights.

I added a couple columns to convert the run time and charge time to minutes in case anyone wanted to use them in a calculation. There were a couple I couldn't decipher from the original data (highlighted in yellow). I added a couple macros so you can re-sort the graphs.